Disperse dye mixtures

ABSTRACT

A dye mixture comprises (A) at least one monoazo dye of formula (I) wherein X A  is Cl, Br, I, CN or NO 2 ; R A  is C 1-4 alkyl or NHCOQ, where Q is C 1-4 alkyl; and each of R A   1  and R A   2 , independently, is C 1-4 alkyl, C 2-4 akenyl, C 1-4 alkoxy-C 1-4 alkyl, aryl-C 1-4  alkyl or aryloxy-C 1-4 alkyl; and (B) at least one pyrroline type dye of formula (II) wherein R B   1  is H, C 1-20 alkyl or C 2-20 alkenyl; and D is aryl.

This invention relates to mixtures of disperse dyes, compositionscomprising dispersions of such mixtures and processes for thecolouration of synthetic materials with such mixtures. Moreparticularly, the invention relates to mixtures of reddish blue monoazodyes with those of the so called pyrroline type, which tend to begreenish blue.

Monoazo dyes of the above type are disclosed in EP-A-0300626 andEP-A-0347685.

As a component of a mixture of dyes, EP-A-0300626 discloses a dye of theformula

where X is Br, Cl or I; Q is C₁₋₄alkyl; and each of R¹ and R²independently is C₁₋₄alkyl or C₂₋₄alkenyl.

Similarly, as a component of a mixture of dyes, EP-A-0347685 discloses adye of the formula

wherein Y is NO₃ or CN, R¹ is alkyl aralkyl alkoxyalkyl or alkenyl andR² is alkyl, aralkyl, alkoxyalkyl, alkenyl, chloroalkyl, aryloxyalkyl oralkoxycarbonyalkyl. Such dyes are in admixture with, for example,monoazo-dyes containing a thiophene nucleus.

WO-A-97004030 discloses mixtures of the following dye with a thiophenedye in various proportions.

Dyes of the abovementioned pyrroline type are disclosed, for example, inU.S. Pat. No. 3,013,013, U.S. Pat. No. 3,013,018, GB-A-2191498,EP-A-0327077, EP-A-0511625 and WO-A-94010248.

In particular, WO-A-94010248 discloses dyes of the pyrroline type havingthe formula (1).

wherein:

D is a group of the Formula (2)

 or a group of Formula (3):

 or a group of the Formula (4)

R¹ is alkyl, cycloalkyl, aryl, a kenyl or aralkyl each of which may beoptionally substituted;

R² is optionally substituted C₇₋₂₀-alkyl; or

R¹ and R² together with the nitrogen atom to which they are attachedform a pyrrolidino or piperidino ring;

R³ is alkyl, alkenyl or aralkyl each of which may be optionallysubstituted, —SO₂alkyl, —SO₂aryl, or —COR in which R is —H or alkyl,phenyl, cycloalkyl or aralkyl each of which may be optionallysubstituted or —H; and

R⁴ is an electron withdrawing group;

R⁶ is optionally substituted C₁₋₁₄-alkyl; or

R¹ and R⁶ together with the nitrogen atom to which they are attachedform a pyrrolidino or piperidino ring;

R⁷, R⁸, R⁹ and R¹¹ each independently is alkyl, cycloaklyl, aryl,alkenyl or aralkyl, each of which may be optionally substituted, or —H;

W is oxygen or sulphur;

Z is a direct link or N—R¹¹ in which R¹¹ is —H or optionally substitutedalkyl or aryl;

Ring A is unsubstituted apart from the —NR¹R² group or is substituted byfrom 1 to 4 further groups; and

Ring B is unsubstituted or substituted by from 1 to 3 groups; except for3-(4-(N,N-di-n-octylamino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrole

provided that:

(a) when D is a group of Formula (3), R¹ and R⁶ are different and R¹ isnot —C₂H₅, —C₃H₇ or —C₁H₉ when R⁶ is —C₂H₄phenyl, —C₃H₆phenyl and ethylsubstituted by —OH, —CN, —OCH₃, —OC₂H₄OC₂H₅, —NHCOCH₂ —Ophenyl and—NHSO₂CH₃; or

(b) at least one of R¹ and R⁶ is branched chain alkyl. Commerciallyavailable dyes of the pyrroline type are, for example, dyes of theformula:

 where R^(A) is H (Kayalon Polyester Brilliant Blue F2B-S); or CH₂CH═CH₂(Kayalon Polyester Blue-Green FG-S); and dyes of the formula

 where X^(A) is C₄H₉ and Y^(A) is CH(CH₃)C₅H₁₁.

It is found that certain mixtures, although giving bright shades onpolyester when viewed in normal daylight, tend to exhibit a “red” flarein tungsten light which is a serious commercial disadvantage.

Although the problem of “flare” may be solved by at least one of themixtures disclosed in EP-A-0347685, such a mixture is especiallysensitive to reduction and has a relatively low heat fastness. Likewiseflare can be avoided by using a dye mixture in which the nitrothiophenecarries an acetyl group. However, such dyes tend to be expensive.

We have found surprisingly that a mixture of dyes, as defined below,surprisingly not only allows reduction or even elimination of the “red”flare, but provides a much brighter shade and is less sensitive toreduction with consequent loss of shade.

Thus, the invention provides a mixture of dyestuffs containing at least

(A) at least one monoazo dye of the formula (I)

 wherein X_(A) is Cl, Br, I, CN or NO₂;

R_(A) is C₁₋₄alkyl (or NHCOQ, where Q is C₁₋₄alkyl); and

each of R_(A) ¹ and R_(A) ² independently is C₁₋₄alkyl, C₂₋₄alkenyl,C₁₋₄-alkoxy C₁₋₄alkyl, aryl-C₁₋₄alkyl or aryloxy-C₁₋₄alkyl; and

(B) at least one dye of the formula (II)

 wherein R_(B) ¹ is H, C₁₋₂₀alkyl or C₂₋₂₀alkenyl; and

D is aryl.

In a preferred dye mixture, in a dye of the formula (I) of the mixture,an especially preferred value of X_(A) is Br or CN, especially preferredvalues of R_(A) are NHCOCH₃, NHCOC₂H₅, CH₃ and C₂H₅ and especiallypreferred values R_(A) ¹ and R_(A) ² are methyl, ethyl and allyl.

Typical especially preferred components (A) in mixtures embodying theinvention are selected from

(A1)a monoazo dye of the formula (I), wherein X_(A) is Br, R_(A) isNHCOR^(X) where R^(X) is methyl or ethyl and each of R_(A) ¹ and R_(A) ²is ethyl;

(A2)a monoazo dye of the formula (I wherein X_(A) is CN, R_(A) is CH₂and each of R_(A) ¹ and R_(A) ² is ethyl; and

(A3) a monoazo dye of the formula (I), wherein X_(A) is CN, R_(A) isCH₂, R_(A) ¹ is methyl and R_(A) ² is 3-phenylpropyl.

The dyes of the formula (I) may be Prepared in a conventional manner bydiazotisation and coupling.

More particularly, for dyes wherein, in formula (I), X_(A) is Cl, Br orI, an amine of formula (III)

 wherein X is

Cl, Br, or I, is dlazotised and coupled with a coupling component of theformula (V)

 wherein R_(A), R_(A) ¹ and R_(A) ² are as defined above

Dyes of the formula (I), wherein X_(A) is CN may be prepared bydiazotizing 2,6-dibromo-4-nitroaniline and coupling to a couplingcomponent of the formula (V) to form a precursor dye and thereaftersubjecting the precursor dye to a copper catalysed cyano exchangereaction using, for example, copper cyanide or a mixture of copper andsodium cyanides, optionally in a solvent such as dimethyl formamide.

Similarly, dyes of the formula (I), whereon X_(A) is NO₂ may be preparedby diazotizing 2-dibromo-4,6-dinitroaniline, coupling to a couplingcomponent of the formula (V) and then subjecting the resulting precursordye to the above copper catalysed cyano exchange reaction.

In the above diazotisation and coupling reactions, the diazotization iscarried out using a diazotising agent, which is preferably nitrosylsulphuric acid, optionally diluted with glacial acetic acid or aphosphoric/acetic acid mixture and preferably at a temperature of 0-10°C., more preferably 0-5° C. and preferably at a pH<1 (say 0.5) up to 7,more preferably 0.5-1, followed by a subsequent increase in pH to 3-4 toisolate the dye.

Reference is now made to component (B), which comprises a pyrroline typedye of the formula (II).

In the compound of the formula (II), D is preferably a group of theformula (a).

wherein each of R_(B) ² and R_(B) ³ independently is alkyl, cycloalkyl,aryl, alkenyl or aralkyl.

In the above formula (II), the alkyl group represented by any of R_(B)¹-R_(B) ³ is preferably a C₁₋₂₀-alkyl, more preferably a C₁₋₁₂-alkyl andespecially a C₁₋₈-alkyl, group. The cycloalkyl group represented byR_(B) ² or R_(B) ³ is preferably a C₄₋₈-cycloalkyl and more preferably acyclohexyl group. The aryl group represented by R_(B) ² or R_(B) ³ ispreferably phenyl. The alkenyl group represented by any of R_(B) ¹-R_(B)₃ is preferably a C₂₋₁₀-alkenyl, more preferably C₂₋₆-alkenyl andespecially a C₂₋₃-alkenyl group, such as allyl. The aralkyl grouprepresented by any one of R_(B) ¹-R_(B) ³ is preferably aphenyl-C₁₋₆-alkyl, more preferably a phenyl-C₁₋₃-alkyl, especiallyphenylethyl or 3-phenylpropyl.

The alkyl group represented by R_(B) ³ is more preferably a C₇₋₁₅-alkyl,still more preferably a C₇₋₁₂-alkyl and especially a C₇₋₉-alkyl group.

The alkyl group represented by R_(B) ¹ is more preferably a C₁₋₆-alkyland still more preferably C₁₋₄-alkyl group.

R_(B) ¹ is especially preferably —H, C₁₋₄-alkyl or C₂₋₃alkenyl, morepreferably —H or C₁₋₄-alkyl and especially —H.

D is preferably a group of Formula (a).

The alkyl groups represented by any of R_(B) ¹-R_(B) ³ may be straightor branched chain alkyl groups. R_(B) ² is preferably C₁₋₁₂-alkyl morepreferably C₁₋₈-alkyl especially unsubstituted C₁₋₈alkyl. R_(B) ³ may beC₇₋₁₂-alkyl and preferably C₇₋₉-alkyl, especially unsubstitutedC₇₋₉-alkyl or may be unsubstituted C₁₋₆-alkyl. Where D is a group ofFormula (a) it is preferred that one or both of R_(B) ² and R_(B) ³ isbranched, more preferably branched at an α- or β-, i.e., 1- or 2-,position. It is preferred that R_(B) ² and R_(B) ³ are different. It isalso preferred that ring A is unsubstituted apart from the NR_(B) ²R_(B)³ group.

A preferred sub-group of dyes of Formula (I) is that in which D is agroup of Formula (a):

R_(B) ¹ is alkyl or —H;

R_(B) ² is alkyl;

R_(B) ³ C₇₋₂₀-alkyl; and

Ring A is unsubstituted apart from the NR_(B) ²R_(B) ³ group.

Another preferred sub-group of dyes of Formula (II) is that in which Dis a group of the Formula (a);

R_(B) ¹ is —H or alkyl;

R_(B) ² is unsubstituted C₁₋₈-alkyl;

R_(B) ³ is unsubstituted C₁₋₆-alkyl;

Ring A is unsubstituted apart from the —NR_(B) ²R_(B) ³ group; and R_(B)² and R_(B) ³ are different or at least one of R_(B) ² and R_(B) ³ is abranched chain alkyl.

An especially preferred sub-group of dyes of Formula (II) is that inwhich D is a group of Formula (a):

R_(B) ¹ is —H;

R_(B) ² is unsubstituted C₁₋₈alkyl;

R_(B) ³ is unsubstituted C₇₋₉alkyl; and

Ring A is unsubstituted apart from the NR_(B) ²R_(B) ³ group.

A further especially preferred sub-group of dyes of Formula (II) is thatin which D is a group of Formula (a);

R_(B) ¹ is —H;

R_(B) ² is n-propyl or n-butyl;

R_(B) ³ is 1-methylhexyl or 2-ethylhexyl; and

Ring A is unsubstituted apart from the —NR_(B) ²R_(B) ³ group;

Typical especially preferred mixtures of components (B) in mixturesembodying the invention are selected from

(B1) a pyrroline type dye of the formula (II), wherein R_(B) ¹ is H,R_(B) ² is C₄H₉ and R_(B) ³ is 1-methyl-n-hexyl (B¹) or a mixturethereof with up to 10%, by weight of component (B1), of a pyrroline typedye B2) of the formula (II), wherein R_(B) ¹ is H and each of R_(B) ²and R_(B) ² is C₄H₉;

(B2) a pyrroline type dye of the formula (II), wherein R_(B) ¹ is H,R_(B) ² is ethyl and R_(B) ³ is n-octyl (B³), or 2-ethyl-n-hexyl (B⁴) ora mixture of dyes (B³) and (B⁴); and

(B3) a pyrroline type dye of the formula (II), wherein R_(B) ² is C₄H₉,R_(B) ³ is phenylpropyl and R_(B) ¹ is H (B⁵) or allyl (B⁶) or a mixtureof dyes (B⁵) and (B⁶).

When R_(B) ¹ is H, dyes of Formula (II) may exist in a tautomeric formrepresented by Formula (IIA):

wherein D is as hereinbefore defined.

The dyes of Formula (II) where D is a group of Formula (a) may beprepared by reaction of an aniline of Formula (III):

in which Ring A is as hereinbefore defined, firstly with a compound ofFormula R_(B) ²X_(B) in which R_(B) ² is as hereinbefore defined andX_(B) is a halogen such as —Cl, —Br or —I or other leaving group, suchas a tosylate, mesylate or alkylsulphonate, in the presence of a basesuch as an alkali metal carbonate or alkaline earth metal carbonate suchas K₂CO₃ or CaCO₃ and secondly with a compound of formula, R_(B) ³X inwhich R_(B) ³ and X are as hereinbefore defined in the presence of abase as above to form an aromatic amine of Formula (IV);

Alternatively the aromatic amine of the Formula (IV) may be prepared byreductive alkylation of the aniline of Formula (III) with an appropriateketone or aldehyde. The reductive alkylation may be performed in aninert liquid medium such as an alcohol or ester optionally in thepresence of an acid such as an aliphatic carboxylic acid, for example,acetic and propionic acids and aromatic sulphonic acid e.g.4-toluenesulphonic acid using a metal or supported metal catalyst suchas palladium or platinum on carbon and hydrogen, optionally at elevatedtemperature and pressure. Alternatively, reducing agents such as sodiumborohydride may be used. After the reductive alkylation a second alkylgroup may be introduced as described above.

The aromatic amine of Formula (IV) is then reacted with a 3-halopyrroleof Formula (V):

in which R_(B) ¹ is as hereinbefore defined and X_(B) is preferably ahalogen such as —Cl or Br to form a compound of Formula (II). Thereaction may be performed in a liquid medium such asN,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulphoxide,suldholane, N-methylpyrrolidone, acetonitrile, toluene ortetrahydrofuran or any mixture thereof and at a temperature from −20° C.to 50° C. The product may be isolated by any convenient means such aspouring the reaction mixture into a mixture of ice and water andrecovering the precipitated product by filtration. The product may bepurified by any convenient means such as trituration orrecrystallisation from organic liquids particularly alkanols such asmethanol, ethanol and esters such as ethylacetate or mixtures thereof.

The 3-halo-2-oxopyrrole of Formula (V) may be prepared by halogenationof a compound which may be represented by Formulae (VI), (VI¹) and (VI²)

with a halogenating agent such as phosphorus oxychloride, phosphorustrichloride, phosphorus pentachloride, thionyl chloride or phosgene at atemperature of from −20° C. to 50° C. in a liquid medium such asN,N-dimethylformamide, N,N-diethylacetamide, dimethylsulphoxide,sulpholane, N-methylpyrrolidone, acetonitrile or tetrahydrofuran. Theproduct may be used without isolation with improvement in yield in thepreparation of compounds so Formula (II) described above or may beisolated by evaporating the liquid medium.

Alternatively a compound of Formula (IV) may be reacted directly withthe compound represented by Formulae (VI), (VI¹) or (VI²) in a liquidmedium such as toluene in the presence of a halogenating agent such asphosphorus oxychloride.

The compounds represented by Formulae (VI) or (VI¹) may be prepared byreaction of diethyloxalate with a compound for Formula (VII);

in the presence of a base such as an alkali metal alkoxide preferably asodium or potassium C₁₋₆-alkoxide and especially sodium or potassiummethoxide, ethoxide, n- or iso-propoxide, n-, iso- or, tertiary-butoxidein a liquid medium, preferably an alkanol such as methanol, ethanol, n-or iso-propanol or n-, iso- or tertiary-butanol, at a temperature offrom 10° C. to 60° C. The product may be isolated by cooling thereaction mixture and collection by filtration.

The compound of Formula (VII) may be prepared by dimerization ofmalononitrile of Formula (VIII):

NCCH₂CN  Formula (VIII)

by reaction with a base such as sodium methoxide in a liquid medium suchas methanol at a temperature of from −20° C. to 60° C. The product maybe isolated by filtration.

A dye of Formula (II) in which R_(B) ¹ is other than —H may be preparedby reaction of the corresponding dye of Formula (II) in which R_(B) ¹ is—H in a liquid medium, preferably an amide such as dimethylformamide oran ether such as tetrahydrofuran or diethylether in the presence of abase, preferably an alkali metal carbonate such as potassium carbonateor an alkali metal hydride such as sodium hydride at a temperature of 0°C. to 120° C. with an appropriate alkylating or acylating agent. WhereR_(B) ¹ is alkyl an appropriate alkylating agent is an alkyl halide,preferably an alkyl iodide, bromide or chloride. Where R_(B) ¹ isalkenyl an appropriate alkylating agent is an alkenyl halide, preferablyan alkenyl bromide. These dyes may be isolated by evaporating the liquidmedium or by filtration from the reaction mixture.

As previously mentioned, component (B) may be a mixture of two or moredyes of Formula (II) wherein R_(B) ¹ to R_(B) ³ inclusive, D and Ring Aare as hereinbefore defined.

In general, in a preferred mixture of components (A) and (B), the ratio,by weight, of component (A): component (B) may be from 95:5 to 80:20inclusive, for example from 85:15 to 35:65 inclusive, or from 70:30 to40:60, depending upon the choice of dyestuff.

In especially preferred mixtures of components (A) and (B), component(A) is selected from,

(A1) a monoazo dye of the formula (I), wherein X_(A) is Br, R_(A) isNHCOR^(X) where R^(X) methyl or ethyl and each of R_(A) ¹ and R_(A) ² isethyl;

(A2) a monoazo dye of the formula (I), wherein X_(A) is CN, R_(A) is CH₃and each of R_(A) ¹ and R_(A) ² is ethyl; and

(A3) a monoazo dye of the formula (I), wherein X_(A) is CN, R_(A) isCH₃, R_(A) ¹ is methyl and R_(A) ² is 3-phenylpropyl; and component (B)is selected from

(B1) a pyrroline type dye of the formula (II), wherein R_(B) ¹ is H,R_(B) ² is C₄H₉ and R_(B) ³ is 1-methyl-n-hexyl (B¹) or a mixturethereof with up to 10%, by weight of component (B1), of a pyrroline typedye (B²), of formula (II), wherein, R_(B) ¹ is H, and each of R_(B) ²and R_(B) ³ is C₄H₉; or

(B2) a pyrroline type dye of the formula (II), wherein R_(B) ¹ is H,R_(B) ² is ethyl and R_(B) ³ is n-octyl (B³), or 2-ethyl-n-hexyl (B⁴) ora mixture of dyes (B³) and (B⁴); or

(B3) a pyrroline type dye of the formula (II), wherein R_(B) ² is C₄H₉,R_(B) ³ is 3-phenylpropyl and R_(B) ¹ is H (B⁵) or allyl (B⁶) or amixture of dyes (B⁵) and (B⁶).

Especially preferred compositions are the following two componentmixtures:

(1) Component (A1)

 where R is CH₃ and/or C₂H₅.

[the dye wherein R is ethyl is commercially available as C.I. DisperseBlue 183]; and

Component (B1)

 [which dye may contain up to 10% by weight of the correspondingN,N-dibutyl compound];

(2) Component (A2)

 [available commercially as C.I. Disperse Blue 366] and Component (B1)

 [as in the above mixture]; and

(3) Component (A3)

 [commercially available as C.I. Disperse Blue 368] and

Component (B1)

 [as in each of the above mixtures].

More especially preferred are mixture (1) of components (A1) and (B1) inthe ratio of 30:10 to 60:40 by weight, mixture (2) of components (A2)and (B1) in the ratio of 70:30 to 40:60 by weight and mixture (3) ofcomponents (A3) and (B1) in the ratio of 70:30 to 40:60 by weight.

A mixture embodying the invention of at least one dye of formula (I)(Component A) and at least one dye of the formula (II) (Component B) mayadditionally comprise at least one other dye (Component C), especially ayellow, orange, red or brown dye capable of producing a navy or blackshade.

Mixtures embodying the invention can be prepared by a number of methodsincluding

(1) Co-crystallisation

Typically, the dyes are dissolved in a hot solvent, for example, byplacing the dyes in a suitable solvent and heating up to the refluxtemperature of the solvent until the dyes are dissolved, thereafterfiltering to provide a solution, and then allowing the solution to cooland crystals to form. The resultant mixture may then undergo furtherprocessing, such as milling and spray drying. Examples of suitablesolvents for this process are organic solvents such as aromatichydrocarbons, chlorinated hydrocarbons, aliphatic hydrocarbons,alicyclic hydrocarbons, alcohols, amides, sulphoxides, esters, ketonesand ethers. Specific examples of organic solvents are toluene, ethylcellosolve, acetone, chlorobenzene, pyridine, dimethyl formamide,dimethylsulphoxide, ethyl acetate, benzene, tetrahydrofuran andcyclohexane.

(2) Co-milling

(a) The dyes are mixed and then milled together to give an intimateblend which is then spray dried to give a solid mixture; or

(b) each dye is milled separately and then mixed in the required ratiobefore spray drying.

(3) Dry Blending

Each dye is spray dried separately and then mixed in the required ratioby a dry blending process.

The mixtures give an especially bright shade without exhibiting a redflare in tungsten light. The mixtures have high colour strength and canbe readily and cost-effectively formulated.

Mixtures embodying the invention provide especially useful disperse dyesvaluable for colouring synthetic textile materials and fiber blendsthereof by exhaust dyeing, padding or printing, and may be formed intodispersions for this purpose. They may also be used in, for example, inkjet printing of textiles and non-textiles, dye diffusion, thermaltransfer printing and in the colouration of plastics.

According to other aspects, the invention provides a compositioncomprising at least the dye mixture and a dispersing agent, surfactantor wetting agent, suitable for providing such a dispersion and also aprocess for colouring a synthetic textile material or fibre blendthereof which comprises applying to the synthetic textile material orfibre blend a mixture comprising at least one dye of the formula (I) andat least one dye of the formula (II).

The synthetic textile material may be selected from aromatic polyester,especially polyethylene terephthalate, polyamide, especiallypolyhexamethylene adipamide, secondary cellulose acetate, cellulosetriacetate, and natural textile materials, especially cellulosicmaterials and wool. An especially preferred textile material is anaromatic polyester or fibre blend thereof with fibres of any of theabove mentioned textile materials. Especially preferred fibre blendsinclude those of polyester-cellulose, such as polyester-cotton, andpolyester-wool. The textile materials or blends thereof may be in theform of filaments, loose fibres, yarn or woven or knitted fabrics.

The mixtures of dyes of formulae (I) and (II) optionally in conjunctionwith other disperse dyes may be applied to the synthetic textilematerials or fibre blends by processes which are conventionally employedin applying disperse dyes to such materials and fibre blends.

Suitable process conditions may be selected from the following

(I) exhaust dyeing at a pH of from 4 to 6.5, at a temperature of from125° C. to 140° C. for from 10 to 120 minutes and under a pressure offrom 1 to 2 bar, a sequestrant optionally being added;

(ii) continuous dyeing at a pH of from 4 to 6.5, at a temperature offrom 190° C. to 225° C. for from 15 seconds to 5 minutes, a migrationinhibitor optionally being added;

(iii) direct printing at a pH of from 4 to 6.5, at a temperature of from160° C. to 185° C. for from 4 to 15 minutes for high temperaturesteaming, or at a temperature of from 190° C. to 225° C. for from 15seconds to 5 minutes for bake fixation with dry heat or at a temperatureof from 120° C. to 140° C. and 1 to 2 bar for from 10 to 45 minutes forpressure steaming, wetting agents and thickeners (such as alginates) offrom 5 to 100% by weight of the dye optionally being added;

(iv) discharge printing (by padding the dye on to the textile material,drying and overprinting) at a pH of from 4 to 6.5, migration inhibitorsand thickeners optionally being added;

(v) carrier dyeing at a pH of from 4 to 6.5, at a temperature of from95° C. to 100° C. using a carrier such as methylnaphthalene,diphenylamine or 2-phenylphenol, sequestrants optionally being added;and

(vi) atmospheric dyeing of acetate, triacetate and nylon at a pH of from4 to 6.5, at a temperature of 85° C. for acetate or at a temperature of90° C. for triacetate and nylon for from 15 to 90 minutes, secuestrantsoptionally being added.

In all the above processes, the dye mixture may be applied as adispersion comprising from 0.001% to 6, preferably from 0.005 to 4%, ofthe dye mixture in an aqueous medium.

A particular aspect of the invention provides a composition comprising amixture of dyes (I) and (II), optionally at least one other disperse dyeand, additionally, optionally at least one further ingredientconventionally used in colouring applications such as a dispersingagent, surfactant or wetting agent. The composition topically comprisesfrom 1% to 65%, preferably 10 to 60%, more preferably 20 to 55%, of thetotal dye mixture in a liquid, preferably an aqueous, or solid medium.Liquid compositions are preferably adjusted to pH 2 to 7, morepreferably pH 4 to 6.

Typical examples of dispersing agent are lignosulphonates, naphthalenesulphonic acid/formaldehyde condensates and phenol/cresol/sulphanilicacid/formaldehyde condensates, typical examples of wetting agent arealkyl aryl ethoxylates which may be sulphonated or phosphated andtypical examples of other ingredients which may be present are inorganicsalts, de-foamers such as mineral oil or nonanol, organic liquids andbuffers. Dispersing agents may be present at from 10% to 200% on theweight of the dye mixtures. Netting agents may be used at from 0% to 20%on the weight of the dye mixtures.

The compositions may be prepared by bead milling the dye mixture withglass beads or sand in an aqueous medium. The compositions may havefurther additions of dispersing agents, fillers and other surfactantsand may be dried, by a technique such as spray drying, to give a solidcomposition comprising from 5% to 65% of dyestuff.

In addition to the above-mentioned application processes, the dyemixtures may be applied to synthetic textile materials and fibre blendsby ink-jet printing, the substrates optionally having been pre-treatedto aid printing. For ink-jet applications, the application medium maycomprise water and a water-soluble organic solvent, preferably in aweight ratio of 1:99 to 99:1, more preferably 1:95 to 50:50 andespecially in the range 10:90 to 40:60. The water-soluble organicsolvent preferably comprises a C₁-C₄-alkanol, especially methanol orethanol, a ketone, especially acetone or methyl ethyl ketone,2-pyrrolidone or N-methylpyrrolidone, a glycol, especially ethyleneglycol, propylene glycol, trimethylene glycol, butane-2,3-diol,thiodiglycol or diethylene glycol, a glycol ether, especially ethyleneglycol monomethyl ether, propylene glycol monomethyl ether or diethyleneglycol monomethyl ether, urea, a sulphone, especiallybis-(2-hydroxyethyl)sulphone or mixtures thereof.

The dye mixtures may also be applied to textile materials usingsupercritical carbon dioxide, in which case the dye formulating agentsmay optionally be omitted.

Embodiments of the present invention will now be described in moredetail with reference to the following Examples, in which parts are byweight unless otherwise stated.

EXAMPLES 1-2 PREPARATION FOR INDIVIDUAL DYES EXAMPLE 1

2-bromo-4-nitro-6-cyanoaniline (24 parts) was stirred at 0-5° C. with amixture of acetic/propionic acids (100 parts, 86:14). Nitrosyl sulphuricacid (35 parts, 40% solution in H₂SO₄) was added gradually at 0-5° C.and the mixture was stirred at that temperature for 60 mins. The diazosolution was added to a coupling mixture ofN,N-diethyl-m-aminoacetanilide (21.6 parts), water (100 parts), conc.sulphuric acid (20 parts) and sulphamic acid (7 parts), stirring at 0-5°C.

After stirring for a further 2 hours, the product was isolated byfiltration, washed with cold water and dried at 50° C. Yield 39 parts.

EXAMPLE 2 Preparation of3-(4-(N-Butyl-N-(1-methylhexyl)amino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrole

i) A mixture of aniline (100 parts), 2-heptanone (220 parts), 4-toluenesulphonic acid (6 parts) and 3% palladium on carbon (5 parts) in a 1liter autoclave was charged with hydrogen to a pressure of SOatmospheres and heated at 150° C. for 40 hours. The cooled reactionmixture was diluted with ethyl acetate, filtered, washed with1N-hydrochloric acid (6×200 parts) and water (2×200 parts), the ethylacetate was separated and dried (MgSO₄) before evaporating to leaveN-(1-methylhexyl) aniline (76 parts, 37%).

ia) In an alternative procedure, N-(1-methylhexyl)aniline was preparedas follows: To an ice cooled, stirred mixture of aniline (28 parts),heptan-2-one (69 parts) and propionic acid (9 parts) was added sodiumborohydride (9.8 parts) portionwise at such a rate as to keep thetemperature less than 5° C. The reaction mixture was allowed to warm upto room temperature and stirred overnight. The reaction mixture waspoured into an ice water mixture and extracted with ethyl acetate. Theorganic phase was washed with water, 2% hydrochloric acid and water. Thedried organic phase was evaporated to leave N-(1-methylhexyl)aniline(53.5 parts, 93%).

ii) A mixture of N-(1-methylhexyl)aniline (76 parts) 1-bromobutane (66parts), anhydrous potasium carbonate (65 parts) and DMF (150 parts) wasstirred while heating under reflux for 41 hours. An additional quantityof 1-bromo butane (44 parts) was added and the mixture stirred whileheating under reflux for a further 19 hours. The cooled mixture waspoured into water (400 parts) and the organic phase separated. Theaqueous phase was extracted with toluene, the organic phases and tolueneextract were combined and washed with water (2×100 arts) beforeevaporating to leave N-butyl-N-(1-methylhexyl)aniline (72.8 parts, 44%)which was purified by vacuum distillation to giveN-butyl-N-(1-methylhexyl)aniline b.pt 73-80° C., 2.6 mm Hg.

iia) In an alternative procedure, N-butyl-N-(1-methylhexyl)aniline wasprepared as follows:

A mixture of N-butylaniline (7.45 Darts), anhydrous potassium carbonate(7.5 parts), 2-bromcheptane (13.5 parts) and DMF (25 parts) was stirreda 130° C. for 86 hours. The reaction mixture was poured into water,saturated with salt and extracted with ethyl acetate. The organic phasewas washed with water, dried (MgSO₄) and evaporated to leaveN-butyl-N-(1-methylhexyl)aniline (11.8 parts, approximately 60%strength). This material had acetic anhydride (10 parts) added to itprior to further use.

iii) A stirred mixture of the disodium salt of4-cyano-5-dicyanomethylidene-3-hydroxy-2-oxo-2,5-dihydropyrrole (23parts) and dry N,N-dimethylformamide (130 parts) was cooled to −5° C. to−10° C. and N-n-butyl-N-1-methylhexyl)aniline containing aceticanhydride (27%, 37 parts) was added followed by the dropwise addition ofphosphorous on chloride (26 parts) whilst maintaining the temperature atless than −5° C. The mixture was allowed to warm to room temperature andstirred for 20 hours. The reaction mixture was poured into a stirredmixture of ice and water (400 parts) and acetone (400 parts) was addedbefore filtering off a solid. The solid was washed repeatedly with warmwater (40° C.) and then dried at 50° C. to yield3-(4-(N-butyl-N-(1-methylhexyl)amino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrole(26.8 parts, 65%). A small sample of this material was slurried inboiling methanol, collected by filtration, washed with methanol anddried at 50° C. to give3-(4-(N-n-butyl-N-(1-methylhexyl)amino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrolem.p.180° C.; λmax (CH₂Cl₂) 662 nm (ε max 60231); M/Z (EI) 415 (M⁺, 20%),400 (15), 372 (12), 344 (100) 288 (33) and 272 (25).

EXAMPLES 3-4 PREPARATION OF MIXTURES EXAMPLE 3

A mixture of 34.3 parts of Component (A1), wherein R^(X) is methyl, and6.75 parts of Component (B1) is prepared by mixing the two dyes togetherand milling them as a 40% aqueous slurry with 20 parts of a hightemperature stable dispersing agent until the dye particle size (meandiameter) is in the range of 0.1-5 microns.

This dispersion is standardised to a liquid brand containing 20.5% ofthe mixture, by the addition of 6.5 parts of a humectant and water (to100 parts). This liquid is especially suitable for use in the directprinting and continuous dyeing of polyester and polyester/celluloseblends and can also be used for exhaust dyeing.

The same dispersion is standardised to a solid brand containing 41% ofthe mixture and 59% dispersing agent, by the addition of the 39 parts ofa temperature stable dispersing agent and drying to either a grain orpowder form in a spray dryer. This product is especially suitable forthe exhaust dyeing of polyester, polyester/cellulose and polyester/woolblends and can also be used for continuous dyeing and direct printing.

A dyebath for the exhaust dyeing of polyester in piece form is preparedby adding 3 mls of an aqueous dispersion of the solid brand (1 g dye in100 ml water at 40-50° C.) to 55.8 ml of de-ionised water and 1.2 ml ofbuffer solution. To this dyebath is added a 5 g piece of polyester andthe whole is held for 45 minutes at 130° C. in a Werner Mathis Labomathigh temperature dyeing machine. After rinsing with water and areduction clearing treatment, the material is dyed a bright reddish blueshade which appears almost identical when viewed under both normaldaylight and tungsten light sources.

EXAMPLE 4

A mixture of 19.7 parts of Component (A2) and 12.17 parts of Component(B1) is prepared by mixing the two dyes together and milling them as a40% aqueous slurry with 20 parts of a high temperature stable dispersingagent until the dye particle size (mean diameter) is in the range 0.1-5microns.

The dispersion is standardised to a solid brand containing 31.9% of themixture and 68.1% dispersing agent, by the addition of 48.1 parts of ahigh temperature stable dispersion agent and drying to either a grain orpowder form in a spray dryer. This product is especially suitable forthe exhaust dyeing of polyester, polyester/cellulose and polyester/woolblends and can also be used for continuous dyeing and direct printing.

A dyebath for the exhaust dyeing of polyester in piece form is preparedby adding 3 mls of an aqueous dispersion of the solid brand (1 g dye in100 ml water at 40-50° C.) to 55.8 ml of de-ionised water and 1.2 ml ofbuffer solution. To this dyebath is added a 5 g piece of polyester andthe whole is held for 45 minutes at 130° C. in a Werner Mathis Labomathigh temperature dyeing machine. After rinsing with water and areduction clearing treatment, the material is dyed a bright reddish blueshade which appears almost identical when viewed under both normaldaylight and tungsten light sources.

What is claimed is:
 1. A dye mixture comprising (A) at least one monoazo dye of the formula (I)

 wherein X_(A) is Cl, Br, I, CN or NO₂; R_(A) is C₁₋₄alkyl or NHCOQ, where Q is C₁₋₄alkyl; and each of R_(A) ¹ and R_(A) ², independently is C₁₋₄alkyl, C₂₋₄alkenyl, C₁₋₄alkoxy-C₁₋₄alkyl, aryl-C₁₋₄ alkyl or aryloxy-C₁₋₄alkyl; and (B) at least one pyrroline type dye of the formula (II)

 wherein R_(B) ¹ is H, C₁₋₂₀alkyl or C₂₋₂₀alkenyl; and D is a group of the formula (a)

 wherein each of R_(B) ² and R_(B) ³ independently is alkyl, cycloalkyl, aryl, alkenyl or aralkyl.
 2. A dye mixture according to claim 1, wherein, in a dye of the formula (I) of the mixture, X_(A) is Br or CN, R_(A) is NHCOCH₃, NHCOC₂H₅, CH₃ or C₂H₅ and each of R_(A) ¹ and R_(A) ² independently is methyl, ethyl or allyl.
 3. A composition comprising a dye mixture according to claim 1 and at least one dispersing agent, surfactant or wetting agent.
 4. A dye mixture according to claim 1, wherein R_(B) ³ is optionally substituted C₇₋₂₀alkyl.
 5. A dye mixture according to claim 4, wherein R_(B) ¹ is H, R_(B) ² is C₄H₉ and R_(B) ³ is 1-methyl-n-hexyl.
 6. A dye mixture according to claim 5, wherein component (B) is a pyrroline type dye (B¹) of the formula (II) wherein R_(B) ¹ is H, R_(B) ² is C₄H₉ and R_(B) ³ is 1-methyl-n-hexyl or is a mixture of the pyrroline-type dye (B¹) with a pyrroline-type dye (B²) of the formula (II), wherein R_(B) ¹ is H, and each of R_(B) ² and R_(B) ³ is C₄H₉, which pyrroline type dye mixture contains up to 10%, by weight of the total weight of the pyrroline-type dye mixture of the dye (B²).
 7. A dye mixture according to claim 4, wherein component (B) is a pyrroline-type dye (B³) or (B⁴), each of the formula (II), or is a mixture of the dyes (B³) and (B⁴ which dye (B³) is a dye wherein R_(B) ¹ is H, R_(B) ² is ethyl and R_(B) ³ is n-octyl and which dye (B⁴) is a dye wherein R_(B) ¹ is H, R_(B) ² is ethyl and R_(B) ³ is 2-ethyl-n-hexyl.
 8. A dye mixture according to claim 1, wherein R_(B) ³ is optionally substituted C₁₋₆alkyl.
 9. A dye mixture according to claim 8, wherein R_(B) ¹ is H or allyl, R_(B) ² is 3-phenyl-n-propyl and R_(B) ³ is C₄H₉.
 10. A dye mixture according to claim 1, wherein the ratio, by weight, of dye (I):dye (II) is from 95:5 to 30:70.
 11. A dye mixture according to claim 10, wherein the said ratio is from 85:15 to 35:65.
 12. A dye mixture according to claim 11, wherein the said ratio is from 70:30 to 40:60.
 13. A dye mixture according to claim 1, further comprising at least one additional dye.
 14. A dye mixture according to claim 1, which comprises, as component (A), a monoazo dye (A1) of the formula (1) wherein X_(A) is Br, R_(A) is NHCOQ, where Q is CH₃ or C₂H₅ and each of R_(A) ¹ and R_(A) ² is C₂H₅, or a mixture of monoazo dyes (A1¹) and (A1²) each of the formula (I) wherein, in each dye, X_(A) is Br, in dye (A1¹) R_(A) is NHCOCH₃ and in dye (A1²) R_(A) is NHCOC₂H₅; and, as component (B), at least a pyrroline type dye (B1) of the formula (II), wherein R_(B) ¹ is H and D is a group of the formula

and optionally up to 10% inclusive by weight of the total component (B) of a pyrroline type dye (B2) of the formula (II), wherein R_(B) ¹ is H and D is a group of the formula


15. A dye mixture according to claim 14, wherein the weight ratio of component (A): component (B) is from 90:10 to 80:20.
 16. A dye mixture according to claim 1, which comprises, as component (A), a monoazo dye (A2) of the formula (I), wherein X is CN, R_(A) is CH₃, and each of R_(A) ¹ and R_(A) ² is ethyl and as component (B), at least a pyrroline type dye (B1) of the formula (II), wherein R_(B) ¹ is H and D is a group of the formula

and optionally additionally up to 10% inclusive by weight of the total component (B) of a pyrroline type dye (B2) of the formula (II), wherein R_(B) ¹ is H and D is a group of the formula


17. A dye according to claim 16, wherein the weight ratio of component (A): component (B) is from 70:30 to 55:45.
 18. A dye mixture according to claim 1, which comprises, as component (A), a monoazo aye (A3) of the formula (I), wherein X_(A) is CN, R_(A) is CH₃, R_(A) ¹ is CH₃ and R_(A) ² is 3-phenyl-n-propyl and as component (B), at least a pyrroline type dye (B1) of the formula (II), wherein R_(B) ¹ is H and D is a group of the formula

and optionally additionally up to 10% inclusive by weight of the total component (B) of a pyrroline type dye (B2) of the formula (II), wherein R_(B) ¹ is H and D is a group of the formula


19. A dye mixture according to claim 18, wherein the weight ratio of component (A): component (B) is from 70:30 to 55:45.
 20. A process for colouring a synthetic textile material or fibre blend thereof, which comprises applying thereto a dye mixture according to claim
 1. 21. A process according to claim 20, wherein the synthetic textile material or fiber blend thereof is a polyester or polyester-cellulose or polyester-wool blend.
 22. A process for colouring a synthetic textile material or fiber blend thereof, which comprises applying thereto a composition according to claim 3, dispersed in an aqueous medium. 